Bell's theorem/Abd

Approaching Bell's theorem

7 September 2015

This is a record of my approach to Bell's theorem. I start with the Wikipedia article, w:Bell's theorem: It quotes an encyclopedia with a comment from Bell..

Bell himself wrote: "If [a hidden variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local. This is what the theorem says."

Poppycock! Not having read the original paper, it occurs to me as likely that this is not the theorem itself, but what Bell wrote it means." A theorem is not a human being and says nothing other than its text. So what is the actual theorem?

First of all, w:Local hidden variable theory. Then w:quantum mechanics. On alternate Tuesdays I think I understand quantum mechanics. The rest of the time I think that anyone who thinks they understand quantum mechanics is crazy. I think that may be on the authority of Richard Feynman, perhaps I'll look that up. However, we can use things without understanding them, under some conditions.

Frankly, I'm not sure I understand what "understand" means. I suspect it is the condition of the brain when a certain chemistry exists. You can get it with certain drugs, or, obviously, there are other conditions that generate the state. It is correlated with being able to make predictions, and it feels good.

from the WP article:

"Bell's theorem, derived in his seminal 1964 paper titled On the Einstein Podolsky Rosen paradox,[4] has been called, on the assumption that the theory is correct, "the most profound in science".[13] Perhaps of equal importance is Bell's deliberate effort to encourage and bring legitimacy to work on the completeness issues, which had fallen into disrepute.[14] Later in his life, Bell expressed his hope that such work would "continue to inspire those who suspect that what is proved by the impossibility proofs is lack of imagination."[14]

I love that! I have seen many impossbility proofs that were just that. They begin with a restricted set of assumptions, and derive impossibility from the assumptions. Reality doesn't respect their restricted set of assumptions, it is so rude. It is not that they are wrong, it is that, to steal someone's phrase (Sagan?), they were not even wrong. Off. Out to lunch. Barking up the wrong tree. Proving, quite precisely, their own lack of imagination.

I see this all the time, in personal psychology, where people believe that they "can't" do something, when what is missing is imagination. "Can't" is an impossibility theorem.

But what is this that has some thinking this is "the most profound [theorem, I presume] in science?"

Pretty quickly I want to see the actual work, the real thing, Bell's actual theorem, not some simplified restatement.

Maybe I won't understand this, but I know something about learning. Expose yourself to the material. Do not require understanding. Just see it. Children learn this way. It is adults who shut down, who are averse to what they do not understand, and who become slow learners. There is another thing that happens as a person matures, it may take more repetitions to learn a thing. However, this is clear: "I don't understand" is a major block to learning, and the solution is not to force understanding (that requires a belief that one does not understand, that there is something wrong,) but to recognize "I don't understand" as an interpretation, a learned reaction. Children don't have it, until they encounter certain traumas.

So where is the paper. The Wikipedia article has a link: Dead link. So, the internet archive: comes to the rescue.

Cool! I have now read Bell's paper, from start to finish. Do I get a barnstar?

It actually starts to make sense. Or maybe that's just brain chemistry. More will be revealed. --Abd (discuss • contribs) 03:48, 7 September 2015 (UTC)

Today, I read Griffiths. . This is what I'm coming to so far. Griffiths treats Bell's theorem as a done deal. That is not the full state of mainstream consensus, but appears to be a majority position. The Sources page lists to a "fringe" article. We can often learn much by studying fringe and mainstream views and comparing. It's easy to dismiss fringe, and popular, too! However, taking Griffith's position as sound, what I notice is the assumptions about causality. Hidden variables have not been ruled out, but they must be global, not local. And so I now see why Bell's theorem might attract some, ah, "fringe or pseudoscientific interpretations." What if there is a "single global cause for all existence?" This takes us right into mysticism, ancient. And, in fact, my own thinking, that there is a Single Reality, in Arabic, al-Haqq, translated as the Truth or the Reality. No hidden local variables. One hidden global cause.

At this point, and quite possibly forever, this is pseudoscience, if asserted as "scientific," because it may not be testable. However, Bell's theorem appears to have whacked the old concept of local causality, the clockwork universe, upside the head. It might not recover. So far, it looks like the case is not closed. More will be revealed. I still cannot say that I have an understanding of the alleged proof, all the way through, though I'm getting much more familiarity with it. --Abd (discuss • contribs) 20:12, 7 September 2015 (UTC)

8 September 2015

Guy posted two links to the page supra: Mermin and Vandegrift. As to the second, yes, Guy has a paper in a journal on this topic, published in 1995, i.e., twenty years ago. All of which makes me appreciate Guy more and more. I will review Guy's paper later. Great stuff. I don't agree with some of his premises, it seems, but I'm never certain about things like that until I do the work. (I've encountered the same occurring with some of what I've seen on the web about Bell's theorem, that there is a black and white view, either A or B. When reality might be C.

Now, the first paper, Mermin, is an approachable description of the "paradox." It uses little math. I still find it overly and unnecessarily complex, so I might attempt to boil the argument down. I read the paper and still am left with a sense that I don't understand something. It's strange, because, at the same time, I have more and more of a sense that I get Bell's theorem and the importance. On Talk:Bell's theorem I talk about the learning process with a bunch of quotes from Richard P. Feynman, who probably shaped my life more than anyone else I ever met. From what I covered in that Talk discussion there, I intend to do that rewrite of Mermin, because it is likely to be highly educational for me. --Abd (discuss • contribs) 03:15, 9 September 2015 (UTC)

9 September 2015

When I spend some days with an issue, I often dream about it, or wake up with ideas. So, that's happening. What I'm coming to I will describe on /Telepathy. Summary: phenomena ascribed to "telepathy" may be unreecognized conjoint causality. As is well known, correlation does not prove caution, i.e., where A is observed, then B, that B is correlated with A does not prove that A causes B. With correlation, there are four logical possibilities: A -> B, B -> A, (C -> A) * (C -> B), or the correlation is noise, which with strong correlation is unlikely. With time sequence, we generally rule out that B causes A. In the experiments addressed by Bell's theorem, it's not relevant, either result is astonishing. From Guy's published paper, it is no wonder that he wrote:

"I do not believe in mental telepathy, miracles or any other occult phenomenon. This affair with Bell’s theorem has shaken me to to the bone."

I'll state it this way: If you are not confused, you do not understand what is happening. (Or you are an incredible genius, and why are you hiding out? Come 'on, share the wealth!) --Abd (discuss • contribs) 14:37, 9 September 2015 (UTC)